libssh2 up to 1.11.1 Sftp src/sftp.c sftp_open double free

CVSS Meta Temp Score
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CTI Interest Score
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5.2$0-$5k0.77

Summaryinfo

A vulnerability, which was classified as problematic, has been found in libssh2 up to 1.11.1. This impacts the function sftp_open of the file src/sftp.c of the component Sftp. The manipulation leads to double free. This vulnerability is referenced as CVE-2026-66032. Remote exploitation of the attack is possible. No exploit is available.

Detailsinfo

A vulnerability was found in libssh2 up to 1.11.1. It has been rated as problematic. This issue affects the function sftp_open of the file src/sftp.c of the component Sftp. The manipulation with an unknown input leads to a double free vulnerability. Using CWE to declare the problem leads to CWE-415. The product calls free() twice on the same memory address, potentially leading to modification of unexpected memory locations. Impacted is availability. The summary by CVE is:

libssh2 through 1.11.1, fixed in commit 5e47761, contains a double-free vulnerability in the sftp_open() function in src/sftp.c that allows a malicious SSH server to corrupt the heap of any authenticated client opening an SFTP session. When a server responds to SSH_FXP_OPEN with SSH_FXP_STATUS containing FX_OK, the response data buffer is freed, and if a subsequent sftp_packet_require() call returns a specific error such as LIBSSH2_ERROR_CHANNEL_PACKET_EXCEEDED, the same pointer is freed a second time, enabling tcache dup conditions on glibc systems that allow overlapping allocations and function pointer overwrites.

The advisory is shared at github.com. The identification of this vulnerability is CVE-2026-66032 since 07/23/2026. The exploitation is known to be easy. The attack may be initiated remotely. Technical details are known, but no exploit is available.

Applying the patch 5e4776146552d898b9c0e1b313cd093fa8dc92d0 is able to eliminate this problem.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-48719). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Name

Version

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.4
VulDB Meta Temp Score: 5.2

VulDB Base Score: 5.4
VulDB Temp Score: 5.2
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Double free
CWE: CWE-415 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Patch
Status: 🔍

0-Day Time: 🔒

Patch: 5e4776146552d898b9c0e1b313cd093fa8dc92d0

Timelineinfo

07/23/2026 CVE reserved
07/24/2026 +1 days Advisory disclosed
07/24/2026 +0 days VulDB entry created
07/25/2026 +1 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-66032 (🔒)
GCVE (CVE): GCVE-0-2026-66032
GCVE (VulDB): GCVE-100-382985
EUVD: 🔒

Entryinfo

Created: 07/24/2026 19:14
Updated: 07/25/2026 19:45
Changes: 07/24/2026 19:14 (56), 07/25/2026 19:45 (1)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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